BEIJING, April 25 (Reuters) - A move by China's authorities
to strip Sina Corp of some online publication licences
as part of a pornography crackdown should be seen as a warning
shot at the country's Internet firms to toe the Party line on
freedom of expression, experts said.

The punishment was also initiated by a regulatory body that
has previously not exercised its power in this way, and is being
widely viewed as a sign that various branches of the government
are clamouring to assert their authority over the Internet.

The revocation of Sina's licences for online literature,
video and audio publication is the harshest in recent memory for
a large Chinese Internet company. But it will inflict minimal
damage to the company which gets most of its money from
advertising on its more popular websites such as those for news,
sport and entertainment.

"It's almost a symbolic move, they're targeting Sina, which
is a big name, because they know everyone will write headlines
about it, but it won't have an impact on the company's revenues
or profits," said Doug Young, a professor at the Fudan
University Journalism School.

"But at the same time it sends a message out to companies,
'Hey, you guys need to be watching your sites and actively
policing it to avoid sensitive content and remove it'," he said,
adding that he did not think other firms would be targeted now
that the message was out.

The licences were revoked after twenty articles and four
videos posted on Sina.com were found by the National Office
Against Pornographic and Illegal Publications to contain "lewd
and pornographic content", the official Xinhua news agency said
on Thursday.

Sina issued a statement that it was sincerely apologetic and
that it is now closely communicating and cooperating with
authorities. It is unclear if or when Sina will get its licences
reinstated.

Shares in Sina, which trades on the Nasdaq, slid more than 7
percent but later pared losses to end 3 percent lower.

ONLINE CRACKDOWN

The move came amid an anti-pornography campaign that was
launched this month and which officials say will last until
November.

But it is also part of a wider crackdown on online freedom
of expression that has intensified after President Xi Jinping
came to power early last year, and which has drawn criticism
from rights groups and dissidents both at home and abroad.

Tencent Holdings Ltd's social messaging app,
WeChat, was also targeted last month, with dozens of widely read
public user accounts run by outspoken columnists shut down. Last
year, there was a move to purge online rumour-mongering which
was seen by free speech advocates as a tool to punish critics of
the ruling Communist Party.

New centres of power created under Xi have likely caused
regulators with varying degrees of authority over the Internet
to jockey for position and recognition.

"There's a bit of competition for who's in charge of the
Internet, so people have to be seen to be getting notches in
their belt," said Duncan Clark, chairman of BDA, a Beijing-based
tech advisory.

"To retain your power and not lose your power you need to be
seen to enforce. What this does is make people nervous: who's
next? It seems like there's change in the air."

Zhan Jiang, a journalism professor at the Beijing Foreign
Studies University, also argues that the move by the National
Office Against Pornographic and Illegal Publications was one
with little legal justification.

"If Sina are guilty of such behaviour it should be punished
by the Ministry of Industry and Information Technology or the
State Council Information Office," he said.

According to Zhan, this is the first time an Internet
company has been punished by the office, which usually targets
traditional media, and Sina's publication of pornography isn't
unique to China's large Internet firms.
(Additional reporting by Megha Rajagopalan and Beijing
Newsroom; Editing by Edwina Gibbs)